export interface CreditAdjustment {
  id: string;
  customerId: string;
  cents: number;
  reason: string;
  agent: string;
  at: string;
}

export class CreditLedger {
  private rows: CreditAdjustment[] = [];

  add(row: Omit<CreditAdjustment, 'id' | 'at'> & { id?: string; at?: string }): CreditAdjustment {
    const rec: CreditAdjustment = {
      id: row.id || `crd_${Date.now().toString(36)}`,
      customerId: row.customerId,
      cents: row.cents,
      reason: row.reason,
      agent: row.agent,
      at: row.at || new Date().toISOString(),
    };
    this.rows.unshift(rec);
    return rec;
  }

  list(customerId?: string): CreditAdjustment[] {
    return customerId ? this.rows.filter((r) => r.customerId === customerId) : this.rows;
  }
}